Distributor for boiler heating surfaces



March 17, 1959 H. OESTREICH I 2,877,746

DISTRIBUTOR FOR BOILER HEATING SURFACES Filed June 15, 1956 HEM/z@EsmE/ch' 4, Man);

h-rolue'y Inventor.-

DISTRIBUTOR FOR BOILER HEATING SURFACES Heinz'fles'treich,Hannover-Herrenhausen, Germany, as slgnor to Heinrich Vorkauf,Beriin-Schmargendorf, Germany Application June 15, 1956,,SerisLNo.591,634 Claims priority, application Germany .lune'27, 1955- 7 Claims.(Cl. 122-406) whereas the tubes more remote from these connections donot receive enough.

The invention aims, therefore, to improve'the water distribution inboilers or steam generators of the mentioned type, andto accomplish suchimprovement by dividing the water current at the end of a distributorinto two' or 'more than two currents and to cause these-currents toenter the distributor over the length of the latter.

Another object of the invention is the provision of means to influencethe distribution of the water over the length of the distributor bydividing the water flow, and, in certain instances, to supply a largerquantity, of water to very intensely heated portions than to less heatedportions of the heating surface tubes.

A further object of the invention is to prevent totally or partly thethrottle losses on account of-suctioneddies taes atent If the below eachriser tube from becoming effective over the total length of thedistributor, so that such'l'os ses affect, at most, a small number of,tubes.

In boilers or steam generators according to the invention, the advantageof wide down pipes will be fully utilized inasmuch as the velocity offlow is much higher in :downpipes which are wide and few innumberwithout causing an increase of the pressure drop, than in a largernumber of down pipes of small diameter. Owing to the velocity prevailingin the wide down pipes, the kinetic energy of the water can be utilizedto cause differences of the water pressure of the individual currentsstarting therefrom.

According to another object of the invention, special connecting tubesmay be provided to the portions of the distributors which are fartherremote from the connections of the down pipes, and such connecting tubesare preferably so arranged that they extend from points underneath theconnections of the down pipe and the distributor. Such arrangementoffers the advantage that owing to the dynamic pressure here created,the water will be forced into the connecting tubes extending from thesepoints. The connecting tubes suitably lead the water to the median partof the distributor where generally in furnaces with rectangular plan,the radiantly heated tubes are more intensely heated than at the ends.

The distributors with their connecting tubes extending from the downpipes may be formed like trellis girders, which have a much highermoment of resistance than a conventional distributor of the same passagecross-see tion. Such distributors, formed as girders, are especiallyadvantageous if they are used as supports of a large heat- 2 inggsurface; e. g. a large number of banks of tubes, to which the .water isadmitted from the distributors. Distribu'tors', formed astrellisgirders, render it possible to carry not only the heating'surfacebut also fire clay bricks, deflectingwalls or the like;

Further -objects and details of "the invention will be apparent from thedescription given hereinafter and the accompanying drawing illustratingan embodiment thereof byyway' of example.

In the drawing,

Fig. "l is a longitudinal cross-section of a steam generatorincorporating the invention, and

Figs: 2 to 4 are three diiferent distributors of the em bodiment ofFig.1 in diagrammatic elevations and with the connecting tubes extendingbetween the distributors and the down pipes.

' Referring now to the'drawing.-

Fig.1 shows a steam generator with gravity circulation; however, it isto be understood that the invention is. ap plicable also to otherboilers with gravity circulation, such as to certain hot water boilers.The term boiler appears ingv in the claims is, therefore, to beunderstood to include all kinds of boilers to which the invention isapplicable.

'The radiantly heated surface consists of several groups of tubes.The'front wall tubes 11 extend from the water distributor 12. They openinto the upper collector 13. The rear wall tubes 14 extend from thedistributor 15 to the upper collector. 16. The side wall tubes 17 extendfrom the lower longitudinal distributor 18 to the upper longitudinalcollector 19. The upper collectors 13, 16 and 19' are'connectedwith thesteam drum 20. The namedigroups of tubes 11,14 and 1'7 substantiallyline the furnace walls. In a downwardly directed flue, another group 21is arranged consisting of tubular .elements whioh'are connected to thedistributor 22 and open also into .the'c'ollector 16. The heated tubesystem is supplied with water by the vertical pipes 23 which are notheated and'extend from both ends of the steam drum 20 downward.Furthermore, there areprovided the return tubes 24 and 25 which bypassthe drum and conduct water separated in the upper longitudinalcollectors 19, directly to the' lower distributors.

The down pipes 23 and return pipes 24 and 25 have a relatively largecross section and form, together with the lower'distributors and uppercollectors, a tubular frame work carrying the heating surfaces. In thistype of boil.- er "structure, a relatively high velocity prevails in itsfew down and return pipes.- In order to avoid current-losses due tothese high water velocities at the points where the water enters thelower distributors, special admission tubes to the distributors areprovided according to the invention.

For this purpose, in Fig. 1, special admission tubes 26 lead from thelower ends of the down pipes 23 and the return pipes 24 to the lowerlongitudinal distributor 18 so that this distributor 18, on the onehand, receives water from its ends directly through the down and returnpipes and, on the other hand, through the admission tubes 26 which,however, conduct the water to the median part of the distributor where,as well known, the most intensely radiantly heated tubes are connected.Through these admission tubes 26 the distribution of the water over thelength of the distributor 18 will be essentially improved and thecurrent loss decreased.

The distribution of the water to the front wall distributor 12 isprovided in a similar manner.

Another tube 27 is positioned parallel to the distributor 12. Bothtubes, the distributor 12 and also the tube 27, are connected at theirends to the water circulation by means of the connecting tube 28.

on alarger scale.

It will be seen that the distributor 12 is connected at its ends withthe connecting tubes 28. The admission tube 27 is located abovedistributor 12. The intermediate tubes 29 extend from this tube 27 sothat water is admitted to the distributor 12 not only from its ends inthe conventional manner, but also from the tube 27 through the tubes 29whereby the median evaporating tubes, i. e. particularly the mostintensely heated ones, receive additional water.

Fig. 3 shows the admission of the water to the rear wall distributor 15.Both ends of this distributor are connected to the return tubes 24.

Above the distributor and parallel to the latter, the admission tube 30is located which similarly, as described hereinbefore, is connected withthe distributor 15 through tube 29 so that through these tubesadditional water can flow to the median portion of the distributor. Boththe lateral tubes 29 are inclined which is favorable from the view pointof the flow. It is also to be noted that a kind of trellis girder isformed by the intermediate tubes 29, the distributor tube 15 and theadmission tube 30. This type of structure enables it to be subjectedalso to high mechanical stresses or loads. Thus, in the present case,this trellis girder serves to support the bundle of tubes 21.

Fig. 4, finally, shows the admission of the water to the distributor 22of the set of tubes 21. structure described hereinbefore, thedistributor 22 is con nected with its ends to the return tubes 25. Thetube 31 is provided as an additional admission tube which is alsoconnected with the distributor 22 by the intermediate tubes 29. Also inthis case, tube 31 constituting the lower beam, together withdistributor 22 forms a girder which is braced by the intermediate tubes29 so that, in addition to the improved water distribution, a greaterstrength of the distributor 22 is achieved to support the set of tubes21. i

It will be apparent to those skilled in the art that many alterationsand modifications of the structure shown and hereinbefore described canbe made without departure from the essence and spirit of the inventionwhich for this reason shall not be limited but by the scope of theappended claims.

I claim:

l. In a boiler with gravity circulation, the combination of a pair ofwater-conducting down pipes, a substantially horizontal distributorconnected with its ends to said down pipes, respectively, a plurality ofrisers extending from said distributor, a water admitting tubesubstantially in a vertical plane with and at a distance from said distributor and being in communication with said down pipes,

Similar to the v respectively, and a plurality of connecting tubesconnecting said water-admitting tube to said distributor intermediateits ends.

2. A combination of boiler tubes as in claim 1, said water admittingtube being substantially parallel with said distributor.

3. A combination of boiler tubes as in claim 1, said dis. tributor, saidwater admitting tube and said plurality of connecting tubes being formedsubstantially as a trellis girder adapted to support other weightyportions of said boiler.

4. A combination of boiler tubes as in claim 1, said distributor beingsubstantially horizontal and said water admitting tube being parallel tosaid distributor and connected to said down pipes at a distance abovethe connection of said distributor with said down pipes.

5. A combination of boiler tubes as in claim 1, wherein at least two ofsaid connecting tubes are inclined.

6. In a boiler with gravity circulation, the combination of a pair ofwater conducting vertical down pipes, a substantially horizontaldistributor parallel to the plane defined by said down pipes, tubularconnecting pieces between the ends of said distributor and said downpipes, respectively, a plurality of risers extending from saiddistributor, two upright tubes connected with their ends to the ends,respectively, of said distributor, another tube substantially parallelto said distributor and connected with its ends to the upper ends,respectively, of said upright tubes, and a plurality of connecting tubesbetween and opening into said distributor and said parallel tubeintermediate their ends.

7. In a boiler with gravity circulation, the combination of a pair ofwater conducting down pipes in corners of said boiler, a substantiallyhorizontal distributor cndwise connected to the lower ends of said downpipes, a plurality of risers extending from said distributor, a tube inthe plane of said distributor and said down pipes andvconnected to thelatter at their lower ends, said tube being bent so as to have a lowestpoint underneath the middle of said distributor, and at least threeconnecting tubes, one of which connecting the middle of said distributorand said first mentioned tube and the other connecting tubes connectingsaid distributor and said first mentioned tube intermediate their endsand their middles.

References Cited in the file of this patent UNITED STATES PATENTS2,231,872 Bailey et al. Feb. 18, 1941 FOREIGN PATENTS 580,671 GreatBritain Sept. 16, 1946 673,154 Great Britain June 4, 1952

